Display screen having a graphical user interface



FIG. 1 is a front view of display screen having a graphical user interface showing the new design;

FIG. 2 is a front view of a display screen having a graphical user interface showing an alternate embodiment; and,

FIG. 3 is a front view of the display screen having the graphical user interface shown in FIG. 1 in a different configuration.

The broken lines represent photographs in the graphical user interface and an environment of use and form no part of the claim. 

CLAIM The ornamental design for a display screen having a graphical user interface, as shown and described. 